I just burned an hour of time trying to get my computer started after what appeared to be a serious error stopped Windows XP from booting. Apparently, I ran into a "mup.sys" problem. This came on the heels of a premature shutdown, which may've caused corrupt sectors on my primary hard drive.
After spinning my wheels and wondering which of the many suggested solutions to try, I remembered that I have a secondary external hard drive plugged into a USB port. I promptly used the Acronis True Image startup CD-ROM to restore mup.sys and other drivers (just in case!), then restarted. Operation successful and I'm here now, thanx goodness! And the hour I spent is little compared to some of the more complicated things I saw out there.
Incidentally, I purchased a tertiary hard drive the other day as part of Dell's Days of Deals — Cdn$89 for an external 250 gigger looked like a pretty good deal to me. It's an Aluratek, and going to be used for backup purposes too.
I've ramped up my usage of large media files: the raw movie recordings used for my Video Tutorials take up many gigs before being compressed for the final mixdown, and all the snapshots I save to disk are very space-consuming too (I later compress those BMPs into PNGs and JPGs, the latter of which I upload to my Flickr space). In addition, audio recordings, while not as intensive as video, are consuming a few gigs on their own by way of my solo piano recordings.
But enough about my needs! I just wanted to share my personal experiences in hopes if you haven't considered this yet, that you will: getting good backup software and an external hard drive is a wise idea, since it's both inexpensive and easy to do if your needs are basic, and will give you some peace of mind in the long run. So remember: to move forward, you must backup!*
* Saying appropriated from an old Dantz Retropsect ad.